Excretory Products And Their Elimination Lecture-1
Overview Introduction Human Excretory System Urine Formatiorn Function of tubules Mechanism of concentration of the filtrate Regulation of kidney Micturition
Introduction Excretion is the process by which metabolic wastes and other non-useful materials are eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys and skin. Animals accumulate ammonia, urea, uric acid, carbon dioxide, water and ions like Nat, K+, Cl,phosphate, sulphate, etc., either by metabolicactivities or by other means like excess ingestion. These substances have to be removed totally or partially. Osmoregulation is the process of maintaining salt and water balance (osmotic balance) across membranes within the body. The fluids inside and surrounding cells are composed of water, electrolytes, and non-electrolytes. Ammonia, urea and uric acid are the major forms of nitrogenous wastes excreted by the animals.
Nitenous Waste mmona Uric Aid toxless then -D less toxfc then D More toxic D Process Ureoelirm becavse inslvble in wats L)m uric acid Yecquirer Eyampleand Sn insectr mple . Mammals mosh Coelentyt fesh adul amphibian, hvin, n Land, manne shes, tuHles bids, land Yephles
Excretory organs Protonephridia or flame cells- Platyhelminthes (Flatworms, e.g., Planaria),rotifers, some annelidsand the cephalochordate- Amphioxus Nephridia- earth worms and other annelids Malpighian tubules - most of the insects including cockroaches. Antennal glands or green glands - crustaceans like prawns. Kidney - Vertebrates
Sandeep Singh Rao
Qualifications : M. Sc. (Biotechnology),NET with AIR-75 Experience : 3 Year teaching experience in pre-medical NEET(UG) level